Hi. I'm about to start running my second dark heresy campaign. Set upon a large maglev skiff (think Jaba's sailbarge only a bit less nefarious and a bit more 40kish in design) carrying representatives of the noble houses to an auction, it involves the characters investigating the murder of a person of great power within the DeVayne Incorporation. The characters are not acolytes, and at this point im not going to have any inquisitorial presence in the campaign at all. They do follow the dark heresy character paths, and I will be starting them partway up the rank scheme to represent their past experience.

There are two player characters, one of whom is a member of a fledgling house which has recently been propelled to great house status almost by complete coincidence. Due to his family's sudden change in position, he is the first of his bloodline to have been able to afford a true education (he is an adept). This character hasn't been fleshed out that much yet, but his relation to the victim is that of a student. The member of DeVayne had the position of mentor within the great house, and held a career as a lecturer in the college on Scintilla where the PC studied. (I forget its name and I don't have the rulebook to hand).

The second PC belongs to the scum career path. He belonged to the DeVayne Incoporation until around the age of 20, and was destined for great things. However, he was an upstart and didn't fit with the religious ideals DeVayne follows. The mentor character (the victim) had the PC thrown from the great house when he discovered him using obscura. The scum PC spent the next 30 or so years in the lower hive of Hive Sibellus, living a life of crime. Recently he was approached by a man claiming to be a messenger for DeVayne, who issued an invitation from the mentor character to meet on the skiff. However, when the scum PC confronted his former mentor and chooses not to kill him, a shot rings out and the mentor falls dead. Moments later enforcers find the scene and arrest the scum PC.

The campaign involves the scum trying to clear his name by solving the crime he didnt commit, and the adept honouring his teacher by solving the riddle of his death.

Problem is I'm having trouble thinking of interesting clues for the two to follow up on. One clue I'm considering containing is that of bullet calibres, having the PC's sneak into the area where the corpse is being held and examining the wounds to show what kind of weapon was used. I need some ideas for potential tidbits of evidence left at the crimescene and basically a few plotlines.

I want the perpetrator to turn out to be a young enforcer who is working for other members of DeVayne who wanted the mentor dead. I'm considering having him use a reprogrammed work-droid to actually kill the mentor, explaining why the scum didnt notice an enforcer in the noble house's quarters on the skiff. The work-droid thing possibly seems a little weak so im looking to flesh that out a bit. Tell me what you think. I haven't contained all the plot detail (motivation for killing the mentor etc.) here just because there's quite a lot and it would take ages to type.

Anyway, the main thing i need help with is some really cool clues to present my players with!

The first question to be posed would be what time span you want to fill with your mystery. Filling a whole campaign with a single whodunit will be rather difficult. Further, you need a good reason why the scum is "allowed to clear his name" at all - Imperial justice doesn't work on "innocent until proven guilty", especially when the victim and the apparent killer are of such differing status. You'd have to have someone protect the scum. In a normal campaign, I'd say this would be the perfect role for an inquisitor who wants to see whether the scum and the adept would make good acolytes, but you said you don't want the Inquisition involved.

Sorry, I could have cleared up that first problem quite quickly in my original post. The timescale is very short. 3-4 sessions. I'm going to university next year, and the guy who plays the adept is already there. I was hoping to introduce some characters that we could develop in a series of very short campaigns during holidays and stuff when we'll be able to meet up.

As for the second problem, I just haven't decided how to resolve that yet. Either 1) the scum has managed to escape and will have to be extremely sneaky throughout the campaign to avoid rediscovery and capture or 2) the information regarding callibres is discovered quite early, clearing the scum's name. In the second case, I would have the enforcer officer in charge upon the skiff still being suspicious of him, keeping him on board until the investigation is over. I realise this still might seem a bit at odds with existing background regarding imperial justice, but this is an aspect of the 40k universe we as a playing group have often manipulated to make campaigns more feasible. I played inquisitor before dark heresy, and we quite often played characters on the wrong side of the law. We found the absolute justice meted out by the imperium made for a bit less fun (or at least a hell of a lot more work to make our plotlines make sense!) so we just played around with it a bit.

Thanks for the advice, Cifer. Your suggestion for an inquisitor fulfilling that role was something I hadn't yet thought of, and it's something I'll put to the player of the scum next time I see him. It's my understanding, however, that both players want to be involved in something removed from the inquisition.

Just so people know, any clues borrowed from Poirot won't work. I was planning on watching that to get some ideas for the campaign, but it turns out the player of the acolyte owns all of the DVDs and has an encyclopedic knowledge of the murders!

Well, since you were thinking Poirot, perhaps you should take a page from Agatha in setting up your mystery and work backwards.

You need to decide exactly who killed the victim and how. Sit down and write down or figure out exactly how it all went down. Was an Enforcer used as the trigger man? If so, who got him to do the killing? Why did the enforcer go along with the murder? Was he payed off or blackmailed and in what manner was he payed or blackmailed? If he was blackmailed, what was he blackmailed with? Dose anyone else such as the Enforcers family / coworkers / friends know that he received a large sum of money or is being blackmailed? No NPC should ever exist in a vacuum... there are always people that know of or about them and everyone has someone they turn to in order to unburden themselves -it's human nature. Figure out who the trigger man was, who they know and associate with, who they trust and who they hate, and, ultimately, why they did what they did.

Assuming an enforcer was the trigger man, how much planning did he use? No plan is ever perfect, so what went wrong with his? Did he include any accomplices in the murder? If so, did they know what was really going on or did he dupe them? If he did reprogram a servitor, how did he gain the knowledge to do such? Did he have to hire someone else to reprogram the servitor? If so, do they know what they did and why? Why did they help him? If he did it him self, would his tampering be apparent and crude or sophisticated and hard to detect? Where did he gain such knowledge and dose anyone else know he knows how to do such things? If so, who? If he did tamper with a servitor, did anyone see him messing with it or taking it before the murder? Would his interactions with it be stored in it's data banks? If someone saw him, dose he know he was seen and, if so, what will he do about that? In fact, what will he be doing while the murder investigation takes place? Will he be trying to plant additional evidance on the scum and, if so, how would he go about it?

What weapon was used for the murder? Was it a servitor going nuts and beating the man to death or was it a rare gun? Did anyone hear anything?

Who exactly was the victim? Why was he killed? Did he have many enemies and are any of them aboard the boat? Was he traveling with anyone and, if so, where were they when the murder happened? Did the murder stalk his victim or try to get to know him in any way before the murder took place to get a feel for him and, if so, did any of the victims traveling companions notice this? If they did notice, did they think anything of it?

If a trigger man was used, dose ho know who his employers/blackmailers are? If not, what dose he actually know about them? If he dose know them, how deep is his knowledge? What's his feelings towards them? Is he afraid of them, hate them, envy them, all of these? How dose he get in touch with them? If he was payed, how will he git his final payment for the completion of the job? If he's blackmailed, how will he be assured that the blackmail material is destroyed or handed over to him?

Get all of that figured out and you shouldn't need a trail of breadcrumbs. You'll know exactly what happened and what is happening. All you'll need to d is respond to the players and, in such a situation, it would be very difficult for them to suddenly come out of left field asking something or looking into an aspect of the murder that you hadn't planed on in your clue trail.

Oh yes, and don't forget to include a red herring. It's not a proper mystery without one after all ;-)

That was a really great, useful post. All of those questions have really helped me refine the plot and characters. I'm currently working on that quintessential red herring